《自然》20250403出版一周论文导读

 

编译|冯维维

Nature, 3 April 2025, Volume 640 Issue 8057

《自然》，2025年4月3日，第640卷，8057期

物理学Physics

Downscaling micro- and nano-perovskite LEDs

中国科学家研发世界最小尺寸LED

▲ 作者：Yaxiao Lian, Yaxin Wang, Yucai Yuan, Zhixiang Ren, Weidong Tang, Zhe Liu, Shiyu Xing, Kangyu Ji, Bo Yuan, Yichen Yang, Yuxiang Gao, Shiang Zhang, Ke Zhou, Gan Zhang, Samuel D. Stranks, Baodan Zhao & Dawei Di

▲ 链接：https://www.nature.com/articles/s41586-025-08685-w

▲ 摘要：电子学和光子学的许多技术突破都是通过缩小尺寸——使基本设备尺寸更小的过程——实现的。基于Ⅲ-V半导体的发光二极管（LED）的小型化导致了微型LED，这是显示器的“终极技术”。然而，微型LED的生产成本很高，当像素尺寸减小到10μm或更小时，它们会表现出严重的效率损失，限制了它们在商业应用中的潜力。

研究者展示了一种基于钙钛矿半导体的新型LED的缩小尺寸的模型，使其低于传统的尺寸限制。通过局部接触制造方案，可以防止像素边界的非辐射损失，展示了具有数百微米至约90纳米特征像素长度的微米和纳米钙钛矿LED 。对于近红外（NIR）和绿色微型PeLED，在宽像素长度范围内，平均外部量子效率（EQEs）保持在20%左右，在缩小尺寸时表现出最小的性能降低。

该纳米PeLED的特征像素长度低至约90纳米，是目前报道的最小的LED，在所有类别的LED阵列中实现了127000像素/英寸（PPI）的创纪录高像素密度。他们的演示展示了微型和纳米PeLED作为下一代光源技术的优势，具有前所未有的紧凑性和可扩展性。

▲ Abstract：Many technological breakthroughs in electronics and photonics were made possible by downscaling—the process of making elementary devices smaller in size. The downsizing of light-emitting diodes (LEDs) based on Ⅲ–V semiconductors led to micro-LEDs, an ‘ultimate technology’ for displays. However, micro-LEDs are costly to produce and they exhibit severe efficiency losses when the pixel sizes are reduced to about 10 μm or less, hindering their potential in commercial applications. Here we show the downscaling of an emerging class of LEDs based on perovskite semiconductors to below the conventional size limits. Micro- and nano-perovskite LEDs (micro-PeLEDs/nano-PeLEDs) with characteristic pixel lengths from hundreds of micrometres down to about 90 nm are demonstrated, through a localized contact fabrication scheme that prevents non-radiative losses at the pixel boundaries. For our near-infrared (NIR) and green micro-PeLEDs, average external quantum efficiencies (EQEs) are maintained at around 20% across a wide range of pixel lengths (650 to 3.5 μm), exhibiting minimum performance reduction on downsizing. Our nano-PeLEDs with characteristic pixel lengths down to about 90 nm represent the smallest LEDs reported, enabling a record-high pixel density of 127,000 pixels per inch (PPI) among all classes of LED arrays. Our demonstration showcases the strength of micro- and nano-PeLEDs as a next-generation light-source technology with unprecedented compactness and scalability.

Microsatellite-based real-time quantum key distribution

基于微卫星的实时量子密钥分发

▲ 作者：Yang Li, Wen-Qi Cai, Ji-Gang Ren, Chao-Ze Wang, Meng Yang, Liang Zhang, Hui-Ying Wu, Liang Chang, Jin-Cai Wu, Biao Jin, Hua-Jian Xue, Xue-Jiao Li, Hui Liu, Guang-Wen Yu, Xue-Ying Tao, Ting Chen, Chong-Fei Liu, Wen-Bin Luo, Jie Zhou, Hai-Lin Yong, Yu-Huai Li, Feng-Zhi Li, Cong Jiang, Hao-Ze Chen, Jian-Wei Pan

▲ 链接：https://www.nature.com/articles/s41586-025-08739-z

▲摘要：量子网络提供了一种基础设施，将具有革命性计算、传感和通信能力的量子设备连接起来。量子卫星星座为促进全球范围内的量子网络提供了一种解决方案。墨子号卫星验证了卫星量子通信的可行性；然而，扩大量子卫星群是具有挑战性的，需要小型轻型卫星、便携式地面站和实时安全密钥交换。

研究者解决了这些挑战，并报告了一种能够使用便携式地面站执行空间到地面量子密钥分发的量子微卫星的开发。微型卫星有效载荷重约23公斤，便携式地面站重约100公斤，分别减少1个数量级和2个数量级以上。使用这种设置，他们演示了基于卫星的量子密钥分配与多个地面站，并在单次卫星通过期间实现了多达107万比特的安全密钥共享。

此外，他们将卫星—地面双向光通信与量子通信进行多路复用，实现实时密钥蒸馏和安全通信。他们还在中国和南非这两个在地球上相隔12900多公里的地方建立了一个密钥，可以对图像进行一次性pad加密。紧凑的量子有效载荷可以很容易地组装在现有的空间站或小卫星上，为基于卫星星座的量子和经典网络的广泛实际应用铺平了道路。

▲ Abstract：A quantum network provides an infrastructure that connects quantum devices with revolutionary computing, sensing and communication capabilities. A quantum satellite constellation offers a solution to facilitate the quantum network on a global scale. The Micius satellite has verified the feasibility of satellite quantum communications; however, scaling up quantum satellite constellations is challenging, requiring small lightweight satellites, portable ground stations and real-time secure key exchange. Here we tackle these challenges and report the development of a quantum microsatellite capable of performing space-to-ground quantum key distribution using portable ground stations. The microsatellite payload weighs approximately 23 kilograms, and the portable ground station weighs about 100 kilograms, representing reductions by more than 1 and 2 orders of magnitude, respectively. Using this set-up, we demonstrate satellite-based quantum key distribution with multiple ground stations and achieve the sharing of up to 1.07 million bits of secure keys during a single satellite pass. In addition, we multiplex bidirectional satellite–ground optical communication with quantum communication, enabling key distillation and secure communication in real time. Also, a secret key, enabling one-time pad encryption of images, is created between China and South Africa at locations separated by over 12,900 kilometres on Earth. The compact quantum payload can be readily assembled on existing space stations or small satellites, paving the way for a satellite-constellation-based quantum and classical network for widespread real-life applications.

Water structure and electric fields at the interface of oil droplets

油滴界面处的水结构和电场

▲ 作者：Lixue Shi, R. Allen LaCour, Naixin Qian, Joseph P. Heindel, Xiaoqi Lang, Ruoqi Zhao, Teresa Head-Gordon & Wei Min

▲ 链接：https://www.nature.com/articles/s41586-025-08702-y

▲摘要：界面水表现出丰富而复杂的行为，在化学、生物、地质和工程等领域发挥着重要作用。然而，关于疏水界面上的水的基本性质，如取向顺序、水合氢离子和氢氧根的浓度、不适当的氢键和大电场的存在，仍然存在很多争论。即使使用最先进的实验技术和理论方法，这种争议也源于测量界面系统的挑战。

研究者报告了一种溶液中，界面选择性拉曼光谱方法，使用多元曲线分辨率来探测水中十六烷乳液，并借助于拉曼光谱的单体场理论模型。研究结果表明，与平面油水界面相比，油水乳液界面可以表现出降低的四面体顺序和较弱的氢键，以及大量的自由羟基，在其拉伸模式下经历约95cm